What follows is the EIPT excerpt from part II of TiHKAL: The Continuation. This text is reproduced with permission of the author which accounts the first-hand knowledge and experiences of the famous chemist, Alexander Shulgin, with this particular substance. Please view the TiHKAL node for full copyright notice, cautionary note, and ordering information. All formatting and linking was done by hand and may be different than the original printed material. Linked substances in bold below are other chapters from TiHKAL.

TiHKAL #10: EIPT

SYNTHESIS

(from indole)

To a well-stirred solution of 1.6 gindole in 30 mLanhydrous Et2O there was added, dropwise over the course of 30 min, a solution of 3.8 g (2.6 mL) oxalylchloride in 30 mL anhydrous Et2O. Stirring was continued for an additional 15 min during which time there was the separation of indol-3-ylglyoxyl chloride as a crystallinesolid. This intermediate was removed by filtration and washed with Et2O. It was used directly in the following step. This solid acid chloride was added to 3.6 g anhydrous ethylisopropylamine in Et2O, followed by the addition of an excess of 2N HCl. The mixture was cooled, and the resulting product N-ethyl-N-isopropylindol-3-ylglyoxylamide was removed by filtration. The air-dried product weighed 2.2 g (62% yield) and had a melting point of 149-151 °C.
A solution of 2.0 g N-ethyl-N-isopropylindol-3-ylglyoxylamide in 50 mL anhydrous THF was added, dropwise, to 1.5 g LAH in 50 mL anhydrous THF which was well-stirred under an inert atmosphere. This was brought to reflux and held there for 3 h. The reaction mixture was cooled, and the excess hydride destroyed by the cautious addition of wet THF. A 15% NaOH solution was then added until the solids had a loose white cottage cheese character to them, and the mobile phase tested basic by external damp pH paper. These formed solids were removed by filtration, washed first with THF and then MeOH. The filtrate and washings were combined, dried over anhydrous MgSO4, and the solvent removed under vacuum. The residue set up to a crystalline mass weighing 1.6 g (90%). This was recrystallized from pentane to provide N-ethyl-N-isopropyltryptamine (EIPT) as a free base with a mp of 71-73°C. Indole can also serve as a precursor to NET which is easily transformed into EIPT.

To a solution of 0.33 g N-ethyltryptamine base (see NET recipe) in 4 mL isopropanol there was added 1.5 g isopropyliodide and 1.2 g diisopropylethylamine, and this was held at reflux for 36 h. The volatiles were removed under vacuum, and to the residual black oil there was added 100 mL 15% aqueous NaOH. This was extracted with 3x50 mL CH2Cl2, the extracts pooled, the solvent removed, and the residue distilled at the KugelRohr to give 0.24 g (59%) of N-ethyl-N-isopropyltryptamine as a pale amber oil, bp 150-160 °C at 0.11 mm/Hg that did not crystallize. MS (in m/z): C6H14N+ 100 (100%); C3H8N+ 58 (58%); indolemethylene+ 130 (11%); parent ion 230 (1%). This base was converted to the hydrochloridesalt, as described above.

(with 40 mg, orally)

Within the hour, a very mild pre-nausea, which passed off in about 45 minutes. No visual effects at all. The dreams that night weren't quite as satisfying as the excellent, nice, clear, pretty dreams with an earlier 30 mg. trial. The night was full of chopped-up sleep, since I was up about once an hour to pee. Observation: there is some diuretic component to this material. Barely plus 1. Would not bother taking it again.

EXTENSIONS AND COMMENTARY

Clearly this is not an exciting compound. So why go to the extensive bother to make it and test it? For the single reason that the di-isopropyl analogue is totally weird, one of the two weird tryptamines that need to be explored. If everything went as predicted, then nothing would ever be discovered. One must look always for the aberration that will demand that you change your working hypotheses and become responsive to unexpected and unexplainable things. 5-MeO-DET has an unexpected property, a lightheadedness and vertigo at a very small dosage. This may prove to be its value in research, and this is discussed in its own entry. Here is a response to another unexpected observation. N,N-diisopropyltryptamine causes extraordinary auditory distortions. What about this molecule does this thing? Are both isopropyl groups needed? Is only one needed? Might neither be needed, but simply to have something equally massive stuck to that nitrogenatom? This compound, EIPT, is an essential brick in this wall that will contain, define, and describe the fine details of this remarkable CNS property.

This is why EIPT is interesting. Let me itemize these close relatives of the di-isopropylamine analogue, maintaining one isopropyl group but letting the other be something different. What can be seen from all of this exploration?

N1 N2 name action
--------------------------------------------------------------------
methyl isopropyl MIPT It seems to be psychedelic in the 25 mg
area, but it has not been brought up to
the 40 mg level.
ethyl isopropyl EIPT An uncomfortable nausea and uncomfortable
trip but no auditory disruptions.
propyl isopropyl PIPT (not yet evaluated)
isopropyl isopropyl DIPTIntense auditory distortion, at the 40 mg level.
butyl isopropyl BIPT (not yet evaluated)

If it turns out that the di-isopropyl substitution is an absolutely essential structural component of this sensory phenomenon, then it has become one of the most remarkable tools known for the study of the human auditory association area in the brain.

This is why all of this research is important. You can never tell what a new compound will do. So you must continue to make new compounds and you must continue to be the observer. It is truly an exciting world.